Start device for battery igniter

ABSTRACT

An electronic starting circuit including a battery for igniting a lighter. The circuit includes a spark discharge gap for igniting the gas of the lighter. The circuit itself includes an oscillating transformer having a feedback branch and a transistor voltage converter followed by a rectifier to which is coupled a storage capacitor which in turn feeds the spark gap through an ignition transformer.

United States Patent 1191 Get-sing START DEVICE FOR BATTERY IGNITER [75] Inventor: Eberhard Gersing, Gottingen,

Germany [7-3] Assignee: Braun Aktiengesellschaft,

Frankfurt/Main, Germany [22] Filed: Aug. 17, 1973 [21] Appl. No.: 389,250

[30] Foreign Application Priority Data Apr. 10, 1973 Germany 2317940 [52] US. Cl 317/79, 315/183, 317/96,

511 161. C1. F23g 3/00 58 Field ofSearch ..317/79, 80,81,96, 97; 431/27, 70, 264, 266; 315/183, 206, 241

[56] References Cited UNITED STATES PATENTS 3,045,148 7/1962 McNulty 6181 315/183 June 18, 1974 3,311,789 3/1967 Remy 317/96 X 3,383,553 5/1968 Parish et a1. 315/183 3,384,440 5/1968 Mayer.... 431/66 3,584,929 6/1971 Schuette 315/206 X Primary ExaminerVolodymyr Y. Mayewsky Attorney, Agent, or FirmErnest F. Marmorek [5 7 ABSTRACT An electronic starting circuit including a battery for igniting a lighter. The circuit includes a spark discharge gap for igniting the gas of the lighter. The circuit itself includes an oscillating transformer having a feedback branch and a transistor voltage converter followed by a rectifier to which is coupled a storage capacitor which in turn feeds the spark gap through an ignition transformer.

3 Claims, 1 Drawing Figure BACKGROUND OF THE INVENTION This invention relates generally to electronic circuits and particularly relates to a circuit for starting a battery operated igniter particularly suitable for lighters.

Generally such battery igniters are arranged for the purpose of saving the battery so that the voltage converter is switched off after a spark passes through the spark gap. In order to generate a new spark the igniter must be operated again.

In order to operate such an igniter it is usually necessary to ensure excitation of the oscillations. It has already been proposed to use for this purpose a selfwiping contact. Such contacts however are expensive to manufacture and require a relatively large space so that they are not well suited for lighters.

It is accordingly an object of the present invention to provide a starting arrangement of the type discussed which requires little space and which operates safely.

SUMMARY OF THE INVENTION I This problem is solved in accordance .with the present invention by providing an electronic circuit including a base voltage divider consisting of a resistor and a transistor connected in series. The control electrode of this transistor is connected to the cut-out contact of a multiple way switch, while the closing contact of the switch is connected with the pole of the battery having a polarity such that it causes an increase of the conductivity of the base voltage transistor. The cut-out contact of the multiple way switch is connected with one of the feeder conductors of the voltage converter and a capacitor is connected in parallel to the cut-out contact and the multiple way contact of the switch. Such a starting circuit requires only a simple multiple way switch as its only mechanical component. Such a switch may be made relatively small. Furthermore, the circuit requires no more current than a conventional base voltage divider.

According to another embodiment of the invention the base voltage divider includes two resistors between which is arranged the emitter-collector path of the base voltage transistor. The free ends of the two resistors are connected to the feeder conductors of the voltage transformer so that the base of the base voltage transistor provides the control electrode.

Preferably, the feedback branch of the oscillating transformer is arranged in series with the base emitter path of the oscillating transformer and parallel to the resistor of the base voltage divider connected with the cut-out contact of the multiple way switch.

The novel features that are considered characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, as well as additional objects and advantages thereof, will best be understood from the following description when read in connection with the accompanying drawing.

' BRIEF DESCRIPTION OF THE DRAWING The single FIGURE of the drawing is a circuit diagram illustrating a battery igniter provided with a starting circuit in accordance with the present invention.

DECRIPTION OF THE PREFERRED EMBODIMENT The battery igniter illustrated in the drawng includes a battery 1 having a voltage of 3 volts. Connected in parallel to the battery there is provided an electrolytic capacitor 2 which serves the purpose to guarantee the proper operation of the igniter even when the battery has been heavily discharged. The circuit further includes an npn transistor 5 which forms the oscillating transistor of a voltage converter and the emitter of which is connected with a feeder conductor 20 of the voltage converter. The collector is connected by means of the primary winding 6 of an oscillating transformer 9 with the other feeder conductor 21 connected to the positive pole of the battery.

The oscillating transformer further includes a feedback winding 7 as well as the secondary winding 8. The feedback winding 7 is connected with one of its terminals to the base of the oscillating transformer 5 while its other terminal is connected to the junction point of a resistor 4 with the collector of a pnp base voltage transistor IS. The other end of resistor 4 is connected with one of the feeder conductors 20. The emitter of the base voltage transistor 15 is connected by means of a resistor 3 with the other feeder conductor 21.

Between the feeder conductor 20 and the negative pole of the battery 1 there is connected a multiple way switch in such a way that the switching contact 19 is connected with the feeder conductor 20, the closing contact 17 with the negative pole of the battery 1 and the cut-out contact 18 with the base of the base voltage transistor 15. A capacitor 16 is connected in parallel to the cut-out contact 18 and the switching contact 19.

To the secondary winding 8 of the oscillating transformer 9 there is connected a Villard rectifier circuit consisting of a charge capacitor 11, two diodes l2 and 13 and a charge storage capacitor 14. The charge storage capacitor 14 delivers the energy for a spark gap 22 defined by electrodes 31, 32 which is fed by means of a switch 23 such as a thyristor or silicon controlled rectifier and an ignition transformer 24.

The circuit operates in the following manner. In the switching state illustrated in the drawing the multiple way switch 10 is in its rest position wherein the switching contact 19 is connected with the cut-out contact 18. Accordingly, the capacitor 16 is short circuited.

When the multiple way switch 10 is actuated the switching contact 19 is connected to the closing contact 17 so that the charge current of the capacitor 16 renders the base voltage transistor 15 conductive. Accordingly, a current flows through the resistors 3 and 4 so that the operating point of one side of the feedback winding 7 connected to the resistor 4 is raised to a more positive potential so that the oscillating transistor 5 is also driven into a higher state of conduction. As a result, a charge current flows in the primary winding 6 whereby the base voltage is further increased in view of the inductive voltage generated in the feedback winding 7. This process continues until the collector current has reached its maximum value and/or the ion core of the oscillating transformer 9 is saturated. Because the magnetic flux density in the oscillating transformer 9 does not increase any more, there is no more inductive voltage generated in the feedback winding 7 so that the oscillating transformer 5 is blocked.

Due to the change of the collector current before its maximum value is reached a voltage is generated in the secondary winding 8 which charges the capacitor 1 1 by means of the diode 12.

When the oscillating transformer 5 is blocked, an oppositely poled inductive voltage is generated in the secondary winding 8 which added to the voltage of the charge capacitor 11 now charges the charge storage capacitor 14 via the diode 13. As soon as no further charge current flows into the storage capacitor the diode is blocked and the energy stored in the winding capacity of the secondary winding 8 of the oscillating transformer 9 discharges through the oscillating transformer and in turn induces a voltage inthe feedback winding 7 which again renders the transistor 5 conductive and thereby starts a new oscillating cycle.

During the initial oscillations of the converter, however, this energy is not sufficient to excite an oscillation; However, the charge current through the capacitor l6 displaces the operating point of the oscillating transistor 5 so that excitation of the oscillation is guaranteed.

When the storage capacitor 14 is discharged by means of the thyristor 23 and the ignition transformer 24, the winding capacity is practically completely discharged by means of the diode 12. Accordingly, no energy is available to re-excite oscillations as long as no charging'current flows through the capacitor 16. The voltage converter remains at rest until the switch is again actuated.

It will be understood that the circuit specification of the starting circuit of the invention may vary according to the design for any particular application. The following circuit specifications are included by way of example only:

Secondary winding 8 I 250 windings Oscillating transformer 9 9 millimeter pot core Capacitor ll 10 microfarad Diodes 12 and 13 Type 1 N 4001 Charge capacitor 14 0.68 farad PNP transistor type BC 1771:

Base voltage transistor 15 a 0.47 microfarad Capacitor 16 What is claimed is: I

1. Start device for a battery igniter of the type having an oscillating transformer with a feedback branch and including a transistor voltage converter fed by a battery and a following rectifier to which is connected a charge storage capacitor which in turn feeds a spark gap defined by two electrodes by means of an ignition transformer, the feedback branch includinga base voltage divider for the oscillating transformer of the voltage switch contact of said switch being connected with one of the conductors of said voltage converter and a capacitor connected in parallel to said cut-out contact and said closing contact.

2; Start device as defined in claim 1 wherein said base voltage divider includes two resistors between which is connected the emitter-collector path of said base voltage transistor and wherein the free'ends of said resistors are connected to the conductors of said voltage converter and wherein the base of said base voltage transistor forms the control electrode.

3. Start device as defined in claim 2 wherein the feedback branch of said oscillating transformer in series with the base-emitter path of said oscillating transistor is connected in parallel to that one of said resistors of said base voltage divider which is connected to the conductor connected to said switching contact. 

1. Start device for a battery igniter of the type having an oscillating transformer with a feedback branch and including a transistor voltage converter fed by a battery and a following rectifier to which is connected a charge storage capacitor which in turn feeds a spark gap defined by two electrodes by means of an ignition transformer, the feedback branch including a base voltage divider for the oscillating transformer of the voltage converter, the improvement comprising: a series connection of at least a resistor and a transistor forming the base voltage divider, a multiple way switch having a cut-out contact, the control electrode of said transistor being connected to said cut-out contact, the closing contact of said multiple way switch being connected with that pole of said battery having a polarity to cause an increase of the conductivity of said base voltage transistor, the switch contact of said switch being connected with one of the conductors of said voltage converter and a capacitor connected in parallel to said cut-out contact and said closing contact.
 2. Start device as defined in claim 1 wherein said base voltage divider includes two resistors between which is connected the emitter-collector path of said base voltage transistor and wherein the free ends of said resistors are connected to the conductors of said voltage converter and wherein the base of said base voltage transistor forms the control electrode.
 3. Start device as defined in claim 2 wherein the feedback branch of said oscillating transformer in series with the base-emitter path of said oscillating transistor is connected in parallel to that one of said resistors of said base voltage divider which is connected to the conductor connected to said switching contact. 